The present invention relates to an improvement of an image recording/reproducing apparatus which records/reproduces image data with respect to a recording medium capable of recording a large amount of data. The present invention also relates to an improvement of an image recording apparatus and an image recording method for recording image data onto a recording medium capable of recording a large amount of data.
As is well known, an optical disk is spreading widely as a recording medium for digital data in various fields in recent years. The optical disk tends to attain a larger capacity in accordance with improvements of performance of an optical head depending on developments of a laser beam having a short wavelength as well as progress of a high-density recording technique and data compression technique, at present. The recordable data amount increases greatly.
For example, in case of a CD (Compact Disk), a laser beam having a wavelength of 780 nm is used for a disk having a diameter of 12 cm to record digital data of about 650 MB (Mega Bytes). In contrast, a DVD is capable of recording digital data of 4.7 GB (Giga Bytes) which is as about 7 times large as a CD, by using a laser beam having a wavelength of 650 nm for a disk having the same size as a CD.
Further, the recordable data amount of this kind of optical disk has already been enhanced to record moving picture image data, audio data, and sub-image data representing a caption or the like, which are equivalent as a whole to a movie of two hours on one surface, by using a data compression technique based on MPEG2 (Moving Picture Image Coding Experts Group 2) as an international standard of moving picture image compression of a media integration type.
Meanwhile, the optical disk is not limited to read-only use but developments have been made in a data-writable optical disk such as a DVD-RAM (Random Access Memory). Therefore, it is expected that VCRs (Video Cassette Recorders) using tapes as recording media will be replaced with recording/reproducing apparatuses using the above-mentioned kinds of optical disks as recording media in the future.
If a tape as a recording medium which makes sequential access is substituted by a disk which makes random access, the time required for searching data can be shortened greatly. That is, a VCR generally records VISS flags on a tape when recording data, and the data is reproduced at a high speed to retrieve the VISS flags when searching data, thus to realize head-search.
Therefore, in several cases, a VCR sometimes searches a tape from one end to the other end thereof so that a long time is required to search a target position. In addition, in case where VISS flags are recorded at a plurality of positions on one tape, the VISS flags are searched one after another to retrieve one target position, and therefore, a long time is required for search too.
In contrast, in case of an optical disk, recorded data is divided into units called sectors, and the address of a sector as a target position is registered in a TOC (Table of Contents) region. Therefore, in a recording/reproducing apparatus for an optical disk, an optical head is moved in a radial direction of the optical disk toward a target position when searching data, and rapid search can thus be achieved.
Also, in this kind of recording/reproducing apparatus, even when a plurality of addresses of target positions are registered in the TOC region of the optical disk, only the target position selected by a user can be searched without searching the other target positions if the user selects the address of a predetermined target position. In this respect, rapid search can be realized.
Here, in a recording/reproducing apparatus having a search function with respect to an optical disk as described above, for example, the user inputs a title or the like in form of a character code as data for search, and selects a desired title from a plurality of titles displayed on the screen. Thus, the address of a target position recorded in the TOC region is chosen during the search.
However, in this kind of conventional recording/reproducing apparatus, all titles to be selected by the user are displayed as characters on the screen. Therefore, even if a user records a plurality of programs such as movies, dramas, and the like from television broadcasts onto an optical disk and sets respectively titles for search to the programs, it is difficult to select correctly a program as a target from the plurality of titles displayed on the screen and the user easily makes errors in selection.
Hence, the present invention has been made in consideration of the above situation and has an object of providing an image recording/reproducing apparatus capable of performing easy and precise search by making an arrangement such that a part of images recorded in a recording medium can be set as a title image used for search and a desired program can be selected by viewing the title image.
The present invention also has another object of providing an image recording apparatus and an image recording method which are arranged such that a part of images recorded in a recording medium can be recorded as a title image used for search and a desired program can be easily and correctly searched by viewing the title image.
The image recording/reproducing apparatus according to the present invention relates is aimed to an apparatus records/reproduces a plurality of data streams including main image data and each including constituting a program, with respect to a disk-like recording medium, comprising:
additional image information generating means for generating additional image information to be displayed and superposed on a title screen of the program;
sub-image generation means for converting the additional image information generated by the additional image information generating means into a format of sub-image data;
title screen holding means for holding title screen data obtained by multi-layering the sub-image data generated by the sub-image generating means and the main image data which is to form the title screen of the program;
recording start position holding means for holding data representing recording start positions on the recording medium, with respect to the plurality of programs;
recording means for recording the recording start position data held by the recording start position holding means and the title screen data held by the title screen holding means, into the recording medium; and
reproducing means for selecting and searching a program to be reproduced, based on the title screen data and the recording start position data read from the recording medium.
Also, the image recording apparatus according to the present invention is aimed to an apparatus which records a plurality of data streams including main image data and each including constituting a program, with respect to a disk-like recording medium, comprising:
additional image information generating means for generating additional image information to be displayed and superposed on a title screen of the program;
sub-image generation means for converting the additional image information generated by the additional image information generating means into a format of sub-image data;
title screen holding means for holding title screen data obtained by multi-layering the sub-image data generated by the sub-image generating means and the main image data which is to form the title screen of the program;
recording start position holding means for holding data representing recording start positions on the recording medium, with respect to the plurality of programs; and
recording means for recording the recording start position data held by the recording start position holding means and the title screen data held by the title screen holding means, into the recording medium.
Further, the image recording method according to the present invention is aimed to a method for recording a plurality of data streams including main image data and each including constituting a program, with respect to a disk-like recording medium, comprising:
an additional image information generating step of generating additional image information to be displayed and superposed on a title screen of the program;
a sub-image generation step of converting the additional image information generated in the additional image information generating step into a format of sub-image data;
a title screen holding step of holding title screen data obtained by multi-layering the sub-image data generated in the sub-image generating step and the main image data which is to form the title screen of the program;
a recording start position holding step of holding data representing recording start positions on the recording medium, with respect to the plurality of programs; and
a recording step of recording the recording start position data held by the recording start position holding step and the title screen data held by the title screen holding step, into the recording medium.
According to the structures and method as described above, title screen data generated by multi-layering additional image information as sub-image data, which is to be superposed on a title screen of a program, onto main image data which forms the title screen of the program, and data representing a recording start position of each program on an optical disk are recorded on the optical disk. When reproducing a program, selection and search of programs to be reproduced are carried out based on title screen data and recording start position data read from the optical disk.
Since a part of images recorded in a recording medium is set as a title used for selection of a program and a desired program can be selected by viewing the title depending on the image, a desired program can be searched easily and correctly even if the recording medium is developed to have a large capacity and a large number of programs are recorded.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.